Masahiro Nagaoka

Ultrasonography in Tarsal Tunnel Syndrome

The purpose of this study was to clarify the diagnostic value of ultrasonography in tarsal tunnel syndrome.

Activation of human synovial mast cells from rheumatoid arthritis or osteoarthritis patients in response to aggregated IgG through Fcγ receptor I and Fcγ receptor II

OBJECTIVE Substantial evidence suggests that human synovial mast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). A plausible pathway for the activation of synovial MCs is through IgG receptors, given the prevalence of circulating IgG isotype autoantibodies and synovial immune complexes in patients with RA. However, IgG receptor expression on human synovial MCs remains uncharacterized. The aim of this study was to identify which IgG receptor(s) on synovial MCs are responsible for MC activation in immune complexes. METHODS Synovial tissue specimens were obtained from patients with RA or patients with osteoarthritis (OA) who were undergoing joint replacement surgery, and synovial MCs were enzymatically dispersed. Cultured synovium-derived MCs were generated by culturing synovial cells with stem cell factor, and receptor expression was analyzed using fluorescence-activated cell sorting. Mediators released from MCs were measured using enzyme immunoassays or enzyme-linked immunosorbent assays. RESULTS Primary synovial MCs and cultured synovium-derived MCs obtained from both patients with RA and patients with OA expressed Fcε receptor I (FcεRI), FcγRI, and FcγRII but not FcγRIII. Cultured synovium-derived MCs induced degranulation and the production of prostaglandin D2 and tumor necrosis factor α (TNFα) through FcγRI. The aggregation of FcγRII caused histamine release from cultured MCs but not from primary MCs. Histamine release induced by aggregated IgG was significantly inhibited by neutralizing anti-FcγRI monoclonal antibody and anti-FcγRII monoclonal antibody. CONCLUSION With regard to the FcR expression profile, synovial MCs from patients with RA and patients with OA were similar. FcγRI was responsible for producing abundant TNFα from synovial MCs in response to aggregated IgG. Immune complexes may activate synovial MCs through FcγRI and FcγRII.

Scaphocapitate fracture associated with median nerve palsy

Scaphocapitate fracture refers to a combination of fractures in the scaphoid and capitate. In 1956, Fenton reported two cases of scaphocapitate fracture that he termed “naviculocapitate fracture syndrome.” Fortythree cases have been reported since then. However, scaphocapitate fracture associated with median nerve palsy is rare. Our report concerns a case of scaphocapitate fracture associated with median nerve palsy. Treatment involved open reduction and internal fi xation using a Herbert screw.

Phototoxic Effect of Na-Pheophorbide A Toward Osteosarcoma Cells in Vitro Using a Laser Diode

OBJECTIVE The purpose of this study was to investigate the effectiveness of photodynamic therapy (PDT) with Na-pheophorbide A in anticancer treatment, using osteosarcoma cells in vitro. BACKGROUND DATA It has been reported that PDT with chlorophyll derivatives inhibits the proliferation of various cancer cells. However, there have been no reports that have evaluated the effectiveness of PDT in suppressing osteosarcoma cells. MATERIALS AND METHODS Uptake of Na-pheophorbide A into Hu09 cells (osteosarcoma cells) was assayed using fluorescence microscopy following incubation of the cells with 28 μmol/L of Na-pheophorbide A. The viability of Hu09 cells after PDT treatment was assessed using trypan blue dye staining and MTS assays. PDT-induced apoptosis was determined by evaluation of the activity of selected members of the caspase family and by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining of cells. RESULTS Na-pheophorbide A uptake by cells was rapid, being observed after 60 min of treatment, and Na-pheophorbide A persisted in cells for >24 h. PDT treatment decreased cell viability compared with the control group, indicating high cytocidal activity of PDT. This cytocidal effect was dependent upon drug concentration, light dose, and the number of irradiation times. An increase in the number of cells positive for TUNEL staining and increases in the activity of caspases-3, -8 and -9 were observed in the first 2 h after PDT treatment. CONCLUSIONS A cytotoxic effect of PDT with Na-pheophorbide A on an osteosarcoma cell line in vitro was shown. Caspase activity assays suggested that PDT with Na-pheophorbide A induced an apoptotic change in HuO9 cells, mainly via activation of mitochondrial caspase -9 and -3 pathways.